Extensible-support.



W. B; OLIVER. EXTENSIBLE SUPPORT.

1,217,491. APPLICATION FILE? MR. l2. I916. Patented Feb. 27, 1917' I V 2 SHEETS-SHEET I.

Imwnfom William/Ii Oliwr WILLIAM B, OLIVER, 0F COLLING SWOOD, JERSEY.

EXTENSIBLE SUPPORT.

Specification of Letters Patent. Patented Feb, 27,1917.

Application filedApril 12, i916. Seria1No. 90,5 57.

To all whom it may concern Be it known that I, WILLIAM B. OLIvnR,

of Collingswood, in the county of. Camden and State of New Jersey, have invented cer- 5 tain new and useful Improvements in-E'X- tensible Supports, whereof the following is a specification, reference being had to the accompanying drawings.

As one of the most obvious commercial embodiments of my invention is that which adapts it for use in connection with an ordinary telephone stand, I have shown it thus I A V t pin 15, to a lateralprojection 16, upon the applied, in the accompanying drawings,

wherein Figure I, represents a side elevation of the device, the parts being shown in what may be called the retracted position, i. 6., with the arms of the support closely folded together.

Fig. II, is a side elevation, on a diminished scale, showing the position of the parts with the arm extended.

Fig. III, is a partial top or plan view of the parts in the position in which they are shown inFig. II. n

Fig. IV, is a transverse section on the plane IV, IV, of Fig. I, showing the parts on the scale of that figure.

The object of my invention is to provide a light support or bracket-arm, which shall be capable of extension and retraction and which, while easily manipulated in either direction, shall be entirely stable as against the effect of gravity, in any position throughout its range of movement, without the aid of any fastening or securing adjuncts.

Referring now to the figures, the device as a whole is preferably arranged tobe pivotally supported upon a vertical'stud 1,

mounted in a socket 2, which is provided with. a plate 3, adapted to besecured by screws or otherwise to a fixed point of suport.

p A pivotal support upon the stud 1, is afforded by means of a sleeve 5, which fits upon said stud and which is provided with a laterally projecting base-piece 6. Said base piece carries pivot-pins 7, and 8, re-

spectively arranged at a substantial distance from one another and preferably in a line which is inclined to the vertical as indicated.

To the pivot-pin 7, is freely attached a bar 9, whose end may be conveniently mounted in a slot 10, formed in the base piece 6,

' (Fig. III), and traversed by said pin. The

pivot-pin 8, is preferablyv mounteda transverse sleeve 11, integral with the base piece 6, and receives at its respective extremities a compound bar member formed of the two side bars 13, and 14, respectively, which are similar in length to the bar 9, andavhich, as shown in Fig. III, are symmetrically disposed on each side of the plane of the bar 9, s0 that the latter occupies an intermediate position when viewed from a vertlcal (11160171011, At its other extremity the bar 9, is connected by means of a pivot- 13, and 14, the structure thus comprises a parallel motion dev ce, which, for conve'n ience of nomenclature I term the primary one The hinge piece 17, also carries at the opposite side to'that just described, a

secondary parallel motion device, arranged in converse relation to the primary one, that is to say, a rod 22,1is attached at one end to the pivot pin 21, upon a'lateral projection of the hinge piece 17, and is attached at the other end tothe pivot pin 23, upon the end piece 24. A compound bar, formed of the side bars 26, and'27, similar in length to the rod 22, and symmetrically arranged with relation thereto, is mounted at one end upon thepivot-pin 18, and at'the other is connected'to a pivot 30, upon a rearward extension 31, of the end piece 24. The distance betweenjthe centers of the pivots 23, and 30, isequal to the distance between the movement ofthe end piece 24, will always be in a'horizonta'l plane.

In order to render the (IGVlCG SGlf-SUS- taining, in any given position of extension or retraction, I provide the following means.

A pivot-pin 85,.entends across between the centers of the pivots 21, and 18. The end bars 26, and 27, at a point relatively adjacent to the pivotal point 18, and a pivot-pin 36, extends across between the bars 13, and 14, at a substantially similar distance from the pivot 18. A pair of arms 37, and 38, are mounted upon the pivots 35, and 36, respectively, and are pivotally connected together at the point 40, the said arms being similar in length between their respective pivotal points. The arm 38, is, however, prolonged beyond its pivotal point at 36, and is provided with a curved extremity as shown at 39, the configuration of the curved face being such that it will remain in close contact with the inner surface 41, of the bar 9, in all positions of the device, although it is preferably not in frictional contact therewith at all times.

A short link 42, is pivotally attached at 43, to the bar 9, and at 44, to the arm 38, the point of pivotal connection 44, being at a substantial distance from, and, in the instance shown beyond, the pivot 36. Thus in this instance the arm 38, constitutes a lever of the first order.

Analysis of the structure thus constituted will show that it comprises two parallel motion devices, not necessarily similar in length, but arranged in converse relation to one another, and connected to a common central element, in combination with a pair of arms pivotally connected to one another and to corresponding members of the respective parallel motion devices, one of said arms being adapted to form a lever, which is pivotally connected by a link to the other arm of the adjacent parallel motion devlce.

Under these circumstances, the combined elements are capable of free movement toward or away from the point of support at 5, the device responding immediately to pressure applied in a horizontal direction.

It is however, self-sustaining and substan- 1 tially rigid against pressure applled in a,

vertical direction, using the terms vertical, and horizontal with reference to the embodiment shown.

Hence with any weight within the limits of its structural strength applied upon the end piece 24, the device will remain in any position to which it may have been extended, since the downward stress which would tend to produce relative movement of the parts of the secondary parallel motion device, will be transmitted through the arms 37, and 38, and, by the lever action of the arm 38, will produce a stress upon the members of the primary parallel motion device, compensat ing and resisting the downward stress upon the secondary one.

I prefer to provide the rounded face upon the extension 39, of the arm 38, as a safeguard, because any stress which tends to bend the bar 9, toward the bars 13, and 14, or vice versa, will bring the face of the ex tension into contact with the under surface of the bar 9, and thus brace the structure while permitting the desired movement of the parts. I'also prefer to make each parallel motion device a composite structure whose lower element is a double one, but in the claims which do not specifically relate to this feature it may be ignored, since theoretically the bars 13, and 14, are one member, and the bars 26, and 27, are also one member.

I also desire to point out that while the lever constituted by the bar 38, is a lever of the first order, the invention is not necessarily restricted to such a type of lever.

Having thus described my invention, 1 claim:

1. In an extension support, the combination of a base piece; a central hinge piece; an end piece; a pair of bars pivotally connecting the base piece and the hinge piece, to form a primary parallel motion device; a pair of bars pivotally connecting the hinge piece and the end piece, to form a secondary parallel motion device, arranged in converse relation to the first one; a pair of arms pivotally connected to one another, one of said arms being pivoted to a. bar of one parallel motion device, the other arm being pivotally connected to a corresponding bar of the other parallel motion device; and a link pivotally connected to one of said arms at a distance from its pivotal connection to said bar, said link being also pivotally connected to the other bar of that parallel motion device.

2. In an extension support, the combination of a base piece; a. central hinge piece; an end piece; a pair of bars pivotally connecting the base piece and the hinge piece to form a primary parallel motion device; a

second pair of bars pivotally connecting the hinge piece and the end piece to form a secondary parallel motion device, arranged in converse relation to the first one; a pair of arms pivotally connected to one another and to corresponding bars of the respective parallel motion devices, one of said arms being extended beyond its pivotal point in said bar; and a link, pivotally connected to the other bar of that parallel motion device,

and to the extension of said arm, substantially as set forth.

3. In an extension support, the combination of a base piece; a central hinge piece; an end piece; a pair of bars pivotally connecting the base piece and the hinge piece to form a primary parallel motion device; a second pair of bars pivotally connecting the hinge piece and the end piece to form a secondary parallel motion device, arranged in converse relation to the first one; a pair of arms pivotally connected to one another and to corresponding bars of the respective parallel motion devices, one of said arms being extended beyond its pivotal point in said bar; and a link, pivotally connected to the other bar of that parallel motion device and to the extension of said arm, the extended portion of said arm having a curved periphery, arranged in close proximity to said bar, the radius of said periphery varying in correspondence with the distance of said bar from the pivotal point of the arm, in the diiferent posi tions of range of movement of the bar, substantially as set forth.

4. In an extension support, the combination of a base piece; a central hinge piece; an end piece; a bar pivotally connecting the base piece and the hinge piece to form one element of a parallel motion device; a pair of bars pivotally connecting said base piece and said hinge piece to form the other element of a parallel motion device; a bar pivotally connecting the hinge piece and the end piece; a pair of bars pivotally connecting the hinge piece and the end piece to form a second parallel motion device; a pair of bars constituting one element of each of said parallel motion devices having a common pivotal axis at the central hinge piece; a pair of arms pivotally connected to one another and to corresponding members of said parallel motion devices, one of said arms being arranged to constitute alever; and a link connecting said lever to the other member of the parallel motion device, substantially as set forth.

5. In an extension support, the combination of two pairs of elongated members, said pairs respectively forming the long sides of separate parallel motion devices, a base piece forming the short side of one of said parallel motion devices, an end piece forming the remote short side of the other parallel motion device, a central hook piece forming adjacent short sides of said parallel motion devices and common-to both of them, a pair of arms, pivotally connected to one another and to corresponding bars of the respective parallel motion devices, one of said arms-extending beyond its pivotal point in said bar, and a link pivotally connecting to the other bar of that parallel motion device and to the extension of said arm, Whereby any movement of one parallel motion device in the plane of its pivotal points of support will produce a corresponding movement of the other parallel motion device and in the opposite direction, projecting the end supporting piece outward in a substantially direct line at right angles With the mean of the movement of the tWo parallel motion devices. 7

6. In an extension support, the combination of two pairs of elongated members, said pairs respectively forming the long sides of separate parallel motion devices, a base piece forming a short side of one of said parallel motion devices, an end piece forming the remote short side of 'the other parallel motion device, a central hook piece forming adjacent short sides of said parallel'motion devices and common to both of them, a central hinge piece forming the opposite short sides of said parallel motion devices and common to both of them and means whereby the relative opposing movement of the two long sides of the one parallel motion device as they swing about their centers in said base piece, produce a relative longitudinal movement of the opposite long sides of the other parallel motion device and in the opposite direction, whereby the end supporting piece is projected outward in substantially a horizontal line, nullifying the action of gravity and maintaining the support in equilibrum at any point of its movement.

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylvania, this thirty-first day of March, 1916.

WILLIAM B. OLIVER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

